Campaigner Greta Thunberg, fellow activist Vanessa Nakate and other young campaigners, as well as local trade unionists will speak to crowds at the end of the march through the city where the UN summit is being held.
The climate strike organised by Fridays for Future Scotland, with participants marching at 11am from Kelvingrove Park to George Square, comes as the COP26 talks feature events highlighting the voice of young people and education in climate action.
But Ms Thunberg has been highly critical of the two-week conference, claiming it is the most “excluding COP ever” and labelling it a “two week celebration of business as usual and blah blah blah”.
She tweeted on Thursday: “This is no longer a climate conference.
"This is a Global North greenwash festival”.
A group of mothers from around the world, including Rosamund Adoo Kissi Debrah, whose daughter Ella died from an asthma attack as a result of severe air pollution, will be handing in a letter at COP26 calling for an end to new fossil fuel financing for the sake of their children’s health and future.
They will then join the youth strikers marching through Glasgow.
Ms Kissi-Debrah said: “Lots of words and no action – and toxic pollution on our streets – is fuelling a public health crisis that is making our kids sick and threatening their futures.
“We need urgent action now.
“We are calling on world leaders at COP26 to implement the new World Health Organization guidelines, clean up our air and stop our children dying."
Friday’s protest comes ahead of marches on Saturday where tens of thousands of people are expected in Glasgow, with other marches in London and cities around the UK, as well as across the world.
The protests come at the end of the first week of the conference, where countries are under pressure to increase ambition on cutting the greenhouse gas emissions that are driving climate change, to avoid the worst impacts of warming, and to ensure finance for poor countries to tackle the crisis.
Earlier in the week around 120 world leaders gathered at the COP26 summit to set out the action they were taking to tackle the climate crisis.
There have also been announcements on curbing deforestation, phasing out coal and boosting finance flows towards transforming economies to be green.
But shadow business secretary Ed Miliband warned against “shifting the goalposts” to focus on long-term targets and vague announcements in various sectors instead of on urgent action by countries to cut emissions to get the world on track to limit temperature rises to 1.5C.
In an event on Thursday night US special presidential envoy for climate John Kerry said the COP26 summit is a “critical” event which he described as the world’s “last best hope to get us on course”.
Speaking at the CBI dinner, he called on developed countries to help less-developed countries in the fight against climate change and warned trillions were needed from private finance “because no government in the world has enough money” to cope with climate change.